Recently, some interests have alleged that drinking water in different parts of the country contains unsafe levels of disinfection byproducts. Disinfection byproducts (DBPs) are compounds that can result from cleaning tap water and killing the bacteria and viruses that cause illnesses like typhoid and cholera.

Disinfecting water is critical to our health – it is partly responsible for our longer lifespans and for the decrease in child mortality in America over the past century. One hundred years ago, outbreaks of cholera, dysentery, and typhoid were common in U.S. cities, and disinfection technology was a major factor in eliminating them.[1] The World Health Organization and the U.S. Center for Disease Control credit water filtration and disinfection as one of the major advancements of the last century and people have been drinking water with disinfection byproducts for the past 90 years. DBPs are carefully monitored and limited by the U.S. Environmental Protection Agency (EPA).

While these interests allege that levels of disinfection byproducts are unsafe, the EPA sets strict limits on the amount of these compounds that water agencies are allowed to use. Every water agency, including our own local water agencies, must follow these rules. In fact, the EPA tightened those rules in recent years, and water agencies that serve our drinking water to our region meet those limits. All water agencies are required to test their water and report the results in an annual Consumer Confidence Report. The EPA posts links to all local Consumer Confidence Reports here.

Chlorine-based disinfection is particularly important because it protects water as it moves through pipes into our homes. While methods like UV light and ozonation effectively kill dangerous microbes and are often used for treatment of source water, chlorine-based disinfection is still widely used for its reliance in protecting water after it leaves the treatment plant from the local utility.[2]

Some organizations have asserted that better protecting source water would reduce the need to use chemicals like chlorine and chloramine to clean tap water. We support efforts to clean source water because it benefits us all. However, even the cleanest source water should be put through a treatment process to ensure that it is safe for us to drink. The filtration and disinfection processes that we use today have contributed greatly to eliminating epidemics like cholera and typhoid from the developed world. They have contributed to us all living longer and healthier lives.

If you would like to learn more about this issue in-depth, the folks at DrinkTap.org have an excellent article explaining the science involved.